Wonder which model you have? The Series A has a folding stand and the later ones have a rigid cart like the picture on the left. Yes, it does make a difference in the internals too because the pumps are completely different, one has a vertical pump and the other is horizontal. If you're looking to replace the electric motor, there are a couple of different manufacturers to choose from and the drive gear is specific to the particular motor. There should be a plate on the sprayer with the serial number. The last letter is the series code. Manual #312667 Manual #3A3208